The present invention relates to a lubricating grease composition and in particular to a lubricating grease composition for ball bearings.
As the grease for bearings, in particular, ball bearings conventionally used in spindle motors for, for instance, hard disks of computers and recording devices such as CD-R's, there has been used, for instance, those comprising a base oil such as dioctyl sebacate or a pentaerythritol ester; and a thickening agent such as lithium stearate or lithium hydroxy stearate. However, the acoustic life of the bearing has recently become insufficient because of the improvement of bearing precision due to an increase in the recording density and because of the requirement for a higher use temperature of such devices due to an increase in the number of revolution.